University Park, Pa. --- Contrary to previous reports, healthy, well-nourished older women, 60 to 80 years of age, have immune systems that function at levels similar to young women, 20 to 40 years old, a Penn State study has shown.
Dr. Namanjeet Ahluwalia, assistant professor of nutrition and leader of the study, says, "Although previous studies had, for the most part, indicated a general age-related decline in immune function, our study suggests that, when nutritional and health status are maintained, the body's ability to defend itself against viruses, bacteria, or tumor cells may not necessarily be affected with aging per se."
The results suggest that healthy eating habits may offer a natural means to maintain the ability to fight off germs and reduce illness in old age, she adds.
The results of the study are detailed in the current issue of the journal Mechanisms for Aging and Development. The authors are Deanna Krause, Dr. Ahluwalia's former master's degree student; Dr. Andrea Mastro, professor of microbiology and cell biology; Dr. Gordon Handte, medical director of the clinical laboratory at Penn State's University Health Services; Dr. Helen Smicklas-Wright, professor of nutrition; Dr. Mary P. Miles, Penn State postdoctoral researcher; and Dr. Ahluwalia.
The authors note in their paper, "The lack of age-associated changes in immune response in the current study is in contrast to most of the previous literature on aging and immune function where overall adequacy of nutritional status and/or health status were not simultaneously considered in the study design."
In the Penn State study, 75 women between the ages of 60 and 80 were recruited to participate with the assistance of local Agencies on Aging. Thirty-five younger women, ages 20 to 40 were also recruited for comparison. Women between 41 and 59 were not included due to the confounding effects of hormonal changes on immune function associated with menopause.
All of the study participants were screened to exclude individuals with acute or chronic inflammation and other medical conditions. They were also screened for undernutrition, and protein, iron, vitamin B12 and folate status. Analysis and comparison of blood samples from the generally healthy and well-nourished older and young participants showed "most immune parameters were not compromised with aging."
"These findings highlight the importance of simultaneous examination of health and nutritional status in studies of immune function with aging," the researchers write.
In conclusion, the authors add that nutritional status should also be evaluated in conjunction with defining a person's health status and that future studies are needed to examine the interaction of specific nutrients with aging and immune response.
The study was supported by grants from the U.S. Department of Agriculture and the National Cattlemen's Beef Association.
EDITORS: Dr. Ahluwalia is at (814) 863-5830 or at nxa7@psu.edu by email